Fig. 4From: Comparative carcinogenicity study of a thick, straight-type and a thin, tangled-type multi-walled carbon nanotube administered by intra-tracheal instillation in the ratTEM image of MWCNT-A engulfed by an alveolar macrophage. a Fibers are phagocytosed by a macrophage in the alveolus. b A higher magnification of the boxed section in panel A showing a needle shaped MWCNT-A in the cytoplasm (arrow)Back to article page